: Download tools like WinRAR (Windows), 7-Zip (Free/Open Source), or The Unarchiver (Mac).
If you have received and want to see what is inside:
: Right-click the file and select "Extract Here" or "Extract to 9775/" to unpack the files into a folder.
: Use online tools like CloudConvert or EasyZip if you don't want to install software. How to create and extract RAR files in Windows